Alrighty, in case anyone else runs into this issue with sourcing VTL5C4s, I tested Advanced Photonix NSL-32SR2 in the stock circuit and the lead master LDR on resistance was around 500 ohms, and the EQ LDR on resistance was around 50 ohms. @Henz
was kind enough to do some testing in his DRG, his lead master LDR was around 250 ohms, and EQ LDR was around 125 ohms when they were on.
I've replaced the lead master LDR with the NSL-32SR2 as I'm happy with 500 ohms. I also bought two, what appear to be, NOS Vactec VTL5C4s and they should be here on Thursday. Will test that in the EQ, if it doesn't work out I'd be happy with the NSL-32SR2 there, should give a touch higher Q factor to the EQ. In the Mark V they basically shunt straight to ground, so Boogie didn't think having some resistance there was super important